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612212a3 JF |
1 | /* |
2 | * OF helpers for the I2C API | |
3 | * | |
4 | * Copyright (c) 2008 Jochen Friedrich <jochen@scram.de> | |
5 | * | |
6 | * Based on a previous patch from Jon Smirl <jonsmirl@gmail.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | */ | |
13 | ||
14 | #include <linux/i2c.h> | |
15 | #include <linux/of.h> | |
16 | ||
17 | struct i2c_driver_device { | |
18 | char *of_device; | |
19 | char *i2c_type; | |
20 | }; | |
21 | ||
22 | static struct i2c_driver_device i2c_devices[] = { | |
23 | { "dallas,ds1374", "rtc-ds1374" }, | |
24 | }; | |
25 | ||
26 | static int of_find_i2c_driver(struct device_node *node, | |
27 | struct i2c_board_info *info) | |
28 | { | |
29 | int i, cplen; | |
30 | const char *compatible; | |
31 | const char *p; | |
32 | ||
33 | /* 1. search for exception list entry */ | |
34 | for (i = 0; i < ARRAY_SIZE(i2c_devices); i++) { | |
35 | if (!of_device_is_compatible(node, i2c_devices[i].of_device)) | |
36 | continue; | |
37 | if (strlcpy(info->type, i2c_devices[i].i2c_type, | |
38 | I2C_NAME_SIZE) >= I2C_NAME_SIZE) | |
39 | return -ENOMEM; | |
40 | ||
41 | return 0; | |
42 | } | |
43 | ||
44 | compatible = of_get_property(node, "compatible", &cplen); | |
45 | if (!compatible) | |
46 | return -ENODEV; | |
47 | ||
48 | /* 2. search for linux,<i2c-type> entry */ | |
49 | p = compatible; | |
50 | while (cplen > 0) { | |
51 | if (!strncmp(p, "linux,", 6)) { | |
52 | p += 6; | |
53 | if (strlcpy(info->type, p, | |
54 | I2C_NAME_SIZE) >= I2C_NAME_SIZE) | |
55 | return -ENOMEM; | |
56 | return 0; | |
57 | } | |
58 | ||
59 | i = strlen(p) + 1; | |
60 | p += i; | |
61 | cplen -= i; | |
62 | } | |
63 | ||
64 | /* 3. take fist compatible entry and strip manufacturer */ | |
65 | p = strchr(compatible, ','); | |
66 | if (!p) | |
67 | return -ENODEV; | |
68 | p++; | |
69 | if (strlcpy(info->type, p, I2C_NAME_SIZE) >= I2C_NAME_SIZE) | |
70 | return -ENOMEM; | |
71 | return 0; | |
72 | } | |
73 | ||
74 | void of_register_i2c_devices(struct i2c_adapter *adap, | |
75 | struct device_node *adap_node) | |
76 | { | |
77 | void *result; | |
78 | struct device_node *node; | |
79 | ||
80 | for_each_child_of_node(adap_node, node) { | |
81 | struct i2c_board_info info = {}; | |
82 | const u32 *addr; | |
83 | int len; | |
84 | ||
85 | addr = of_get_property(node, "reg", &len); | |
86 | if (!addr || len < sizeof(int) || *addr > (1 << 10) - 1) { | |
87 | printk(KERN_ERR | |
88 | "of-i2c: invalid i2c device entry\n"); | |
89 | continue; | |
90 | } | |
91 | ||
92 | info.irq = irq_of_parse_and_map(node, 0); | |
93 | if (info.irq == NO_IRQ) | |
94 | info.irq = -1; | |
95 | ||
96 | if (of_find_i2c_driver(node, &info) < 0) { | |
97 | irq_dispose_mapping(info.irq); | |
98 | continue; | |
99 | } | |
100 | ||
101 | info.addr = *addr; | |
102 | ||
103 | request_module(info.type); | |
104 | ||
105 | result = i2c_new_device(adap, &info); | |
106 | if (result == NULL) { | |
107 | printk(KERN_ERR | |
108 | "of-i2c: Failed to load driver for %s\n", | |
109 | info.type); | |
110 | irq_dispose_mapping(info.irq); | |
111 | continue; | |
112 | } | |
113 | } | |
114 | } | |
115 | EXPORT_SYMBOL(of_register_i2c_devices); |